peplos

1. an encompassing structure or membrane.

2. in virology, the outer lipoprotein coat of a large virus, surrounding the capsid and usually furnished, at least partially, by the host cell. Called also peplos.

3. in bacteriology, the cell wall and the plasma membrane considered together.

nuclear envelope the condensed double layer of lipids and proteins enclosing the cell nucleus and separating it from the cytoplasm; its two concentric membranes, inner and outer, are separated by a perinuclear space.